1. Field of the Invention
The present invention relates to a movable contact assembly employed in an electromagnetic switch.
2. Description of the Related Art
In general, an electromagnetic switch may be provided between a storage battery and a power converting device in an electric vehicle such as a hybrid vehicle, a fuel cell vehicle, a golf cart, and an electric forklift to perform the function of supplying and cutting off power provided from the storage battery to the power converting device.
The electromagnetic switch may include a stationary contact, a movable contact brought into contact with or separated from the stationary contact, and an electronic actuator for driving the movable contact. The electronic actuator in the related art may include a coil, a stationary core, a movable core, a shaft, and a return string. The coil may generate an electromagnetic force when a current is supplied. The stationary core may be fixed and disposed at the center of the coil. The movable core may be disposed to be approached to or separated from the stationary core.
The shaft may be provided in a slidably movable manner with respect to the stationary core through the stationary core. Furthermore, an end portion of the shaft may be combined with the movable core so as to be moved together with the movable core, and the other end portion thereof may be connected to the movable contact. The return spring may exert an elastic force to the movable core in a direction such that the movable core is separated from the stationary core.
According to the related art, the movable contact and the shaft may be connected to each other in the following structure. A through hole into which an end portion of the shaft can be inserted may be formed at the center of the movable contact. The movable contact may be inserted into an end portion of the shaft through the through hole. In this state, a corking member may be combined with a corking groove formed at an end portion of the shaft from the outside of the movable contact using a punch not to allow the movable contact to be released from the shaft.
However, in the foregoing case, in order to assemble the shaft with the movable contact, the corking member may be combined with the corking groove using a punch in a state that the movable contact is inserted into an end portion of the shaft and then the movable contact and the shaft are fixed to each other by a jig. Accordingly, it may have a drawback that the overall assembly process is complicated and inconvenient.
Furthermore, the movable contact may be supported in a movable manner along an axial direction of the shaft in the state of being inserted into an end portion of the shaft, and a push spring may be provided between the shaft and the movable contact. The push spring may exert an elastic force in a direction such that the movable contact is to be approached to the stationary contact, thereby allowing the movable contact to maintain the state of being in contact with the stationary contact under a predetermined or higher pressure.
In this case, subsequent to inserting the push spring to an end portion of the shaft, the movable contact should be fixed by a jig to disallow the movable contact to be released from the end portion of the shaft by an elastic force of the push spring. In this state, the corking member may be combined with the corking groove from the outside of the movable contact using a punch. As a result, it may have a drawback that the assembly process is further complicated.